Helene is forecasted to bring showers and strong wind gusts to Western Pennsylvania after the storm struck the southeast, resulting in over 20 fatalities and leaving millions without power.
As of midday Friday, Helene has weakened to a tropical storm. It is merging with another area of low pressure over the Mississippi River Valley, which is causing its low pressure and wind field to expand, affecting most states over the eastern third of the United States.
Helene, a Category 4 storm, arrived in Perry, Florida, around 11 p.m. Thursday, with maximum sustained winds of 140 mph, as reported by the hurricane center. Currently, the storm is moving northward.
How strong will wind gusts be in Western Pennsylvania?
In the lower terrain and river valleys west of the Laurel Highlands and the ridges, we can expect sustained winds of 15-20 mph, occasionally gusting up to 30 mph. However, the higher terrain of the Laurel Highlands and the ridges will experience much stronger winds, with gusts reaching upwards of 50 mph at times.
A wind advisory has been issued until 10 p.m. on Friday for parts of Westmoreland and Fayette counties in Pennsylvania, Monongalia and Preston counties in West Virginia, and Garrett County in Maryland. This advisory is in place due to strong winds that can potentially result in the falling of tree limbs and the movement of loose items.
How much rain will Western Pennsylvania get?
Forecasters also anticipate showers and light rains. The majority of the rain will fall south of Pittsburgh, as high pressure and drier air prevent it from moving north during the day. After 6 p.m., scattered showers should continue to move north of Pittsburgh and into northwestern Pennsylvania throughout the evening and overnight.
A dry slot appears to be moving into most of the Pittsburgh area by Saturday, which could result in fewer rain showers, milder temperatures, and even some afternoon sun. By late Saturday afternoon and evening, isolated to scattered showers cannot be ruled out along I-80 and in far southern Pennsylvania.
The remnants of Helene will eventually merge with an upper-level low to the west. That will return to the Pittsburgh area Sunday into Monday night. This will bring heavier clouds and rain showers beginning Saturday night and extending until next Tuesday.
A stronger cold front may bring a few showers late Tuesday, but it will eventually lead to a surge of drier and colder air, clearing the skies by Wednesday afternoon next week.
Estimates for rainfall between Friday night and Saturday morning range from a few hundredths of an inch to 0.25 inches. An extra half-inch of rain is possible from Sunday to Tuesday night.
